In the top part of a double boiler, place the soy milk and margarine, and heat together until the margarine melts. Add the vegan chocolate chips, continue to cook while stirring constantly until the vegan chocolate chips have melted completely and the mixture is very smooth. Use the ganache, warm, as a glaze for cakes or use as a dip or coating for fruit or nuts, or when cool, use as a filling for cakes and desserts. Store any excess in an airtight container in the refrigerator. It can be reheated in a double boiler as needed.